Link support

[demurgos]

The Link header, defined in RFC5988. It was supported in older versions, but was since then disabled in a514a37.

There were a few attempts to reenable the Link header, but they were never completed, here they are from oldest to most recent:

• Add back the typed representation of the Link header #67
• feat: Enable the Link header #91
• Add back the typed representation of the Link header #113

It would be good to finish the work and enable Link support.